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Re: NOT LIKE much faster than LIKE?

Tom Lane <tgl@sss.pgh.pa.us>

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From: Tom Lane <tgl@sss.pgh.pa.us>
To: "Jim C. Nasby" <jnasby@pervasive.com>
Cc: Andrea Arcangeli <andrea@cpushare.com>, pgsql-performance@postgresql.org
Date: 2006-01-11T21:13:20Z
Lists: pgsql-performance 
"Jim C. Nasby" <jnasby@pervasive.com> writes:
> On Wed, Jan 11, 2006 at 09:39:47PM +0100, Andrea Arcangeli wrote:
>> The index only helps the above query with = 0 and not the one with != 0,
>> but it seems not needed in practice.

> I suspect this is because of a lack of stats for functional indexes.

No, it's because != isn't an indexable operator.

			regards, tom lane